WorksheetsEPA 608 Prep: Type II
Total questions: 20
Worksheet time: 10mins
Which of the following always falls under the EPA definition for "major maintenance, service, or repair?"
Replacing an oil filter
Replacing an expansion valve
Replacing a compressor
Replacing an accumulator
Recovering refrigerant from a system in the vapor phase will minimize the loss of which of the following?
water
oil
refrigerant
non-condensables
After system servicing and recharging, why is refrigerant vapor reintroduced to the chiller before refrigerant liquid?
Vapor charging increases pressure slowly, preventing failure of the rupture disk.
Vapor charging is faster than liquid charging.
Liquid charging is more difficult to control than vapor charging.
Liquid charged into a deep vacuum will evaporate and may lower the temperature freezing water in the heat exchanger tube bundle.
In the event of a large release of CFC, HCFC, or HFC refrigerant in a contained area, which of the following is true?
Safety goggles and lined butyl gloves are sufficient.
Self-contained breathing apparatus (SCBA) or leaving the area is required.
Respiratory protection is not required.
Dust masks are sufficient.
A comfort-cooling appliance containing 50 pounds or more of R-22 is found to be leaking beyond the applicable leak rate threshold. Unless granted additional time, how many days to you have to repair the leak and conduct the initial leak verification test?
1 day
10 days
30 days
45 days
What are refrigeration and air-conditioning compressor heaters used for?
To reduce the amount of refrigerant in the oil.
To prevent refrigerant vaporization.
To reduce the amount of entrained water in the receiver.
To prevent acid pitting.
What is a characteristic of a refrigerant oil that is hygroscopic?
It is a good lubricant.
It is crude oil and unrefrined.
It readily absorbs moisture.
It can be left open to ambient air.
An appliance normally containing more than 50 pounds of R-22 refrigerant was found to have a 35% annual leak rate. After the repair, how many successful verification tests are required?
One. Performed before the appliance is recharged.
Two. The first performed before the appliance is recharged, and the second performed after the appliance returns to normal operating conditions.
One. Performed once the appliance returns to normal operating conditions.
Three. The first performed after the appliance returns to normal operating conditions, and the third performed three months later.
Why could a recycling or recovery machine that uses a hermetic compressor overheat when drawing deep vacuums?
It runs faster than other equipment with oil-less compressors.
The motor relies on the flow of refrigerant through the compressor for cooling.
It has a higher compression ratio limit than other equipment.
The oils used in hermetic compressors are a lower viscosity than the oils used in other equipment.
Recovered refrigerant may contain which of the following impurities?
Ammonia, carbon dioxide, and methyl chloride
Sodiom chloride, potassium nitrate, and silicone oil
Sulphur dioxide and methane
Acids, moisture, and oil
After installation of a field-piped split system, the unit should first be pressurized with:
air and leak checked.
R-22 and leak checked.
R-410A and leak checked.
nitrogen and leak checked.
Which of the following is an indicator of a leak in a high-pressure system with a capillary tube?
High head pressure
Low water temperature
Excessive superheat
Frequent purging
Your recovery/recycling machine has R-22 refrigerant in it. You now have to recover refrigerant from an R-410A unit. What must be done before recovery?
Change the recovery cylinder on the recovery machine.
Change the expansion valve on the recovery machine.
Change the filter and expansion valve on the recovery machine.
Remove the R-22 from the recovery unit and change the filter.
Which condition can cause excessive pressure on the high side of a self-contained (active) recovery device?
When the thermal expansion valve is stuck open.
When the capacity of the recovery tank is larger than the charge size of the system.
When there is a large volume of non-condensable gas in the refrigerant being recovered.
When the system is set for no subcooling.
What is the primary purpose of using a vacuum pump in a refrigeration system?
To remove air and moisture from the system.
To increase the system pressure.
To add refrigerant to the system.
To cool the compressor.
Which of the following refrigerants has the highest ozone depletion potential (ODP)?
R-12
R-134a
R-22
R-410A
What is the function of a thermal expansion valve in a refrigeration system?
To heat the refrigerant before it enters the compressor.
To compress the refrigerant gas.
To regulate the flow of refrigerant into the evaporator.
To cool the condenser.
When charging an R-410A system that uses a water-cooled condenser, you must first charge with vapor to a pressure of at least________, before switching to liquid charging.
80 psig
100 psig
120 psig
150 psig
Which of the following is a common symptom of a refrigerant overcharge in a system?
Low head pressure.
Excessive superheat.
High discharge pressure.
Low suction pressure.
What is the function of a condenser in a refrigeration system?
To reject heat from the refrigerant to the surroundings.
To compress the refrigerant gas.
To absorb heat from the surroundings.
To regulate the flow of refrigerant into the evaporator.
